In recent years, there has been increasing demand for cameras (stereoscopic imaging apparatuses) capable of capturing 3D (stereoscopic) images. As methods of capturing stereoscopic images, there have been used a beam splitter type (half mirror type) of capturing images using a half mirror, a side-by-side type (parallel two-lens type) of capturing images using two imaging apparatuses which are physically arranged and installed, and the like. In these capturing types, the imaging apparatuses are mounted on a cradle called a rig and image capture is performed, and thus the degree of freedom of installation of the imaging apparatuses is increased. For example, a distance between two lenses (base-line length, hereinafter, referred to as an IAD (Inter Axial Distance)) capturing stereoscopic images, convergence, or a field angle can be selected with a high degree of freedom.
However, there is a problem in that whereas a degree of freedom is high, great effort and time are necessary for settings and adjustments for each capturing in order to mount the stereoscopic imaging apparatuses on the rig. In addition, there is also a problem in that particularly a rig of an imaging apparatus employing the beam splitter type is a large-scale device, and is not suitable for capturing or coverage in the field. Further, in an imaging apparatus employing the side-by-side type, since the respective optical systems or imagers of the two lenses physically interfere with each other, the IAD may not be shorter than a specific distance defined by disposition positions of the optical systems or imagers. For this reason, for example, in a case of very near capturing of a subject, parallax at a location distant only several meters behind the subject is displayed on a 3D display exceeds a parallax range where people view 3D images with comfort.
For example, JP-A-2003-5313 discloses that a single objective optical system is disposed on the front side (subject side) of a plurality of image forming optical systems, and thereby a convergence point can be moved.